[Vwdiesel] A/C valve question and wanted

[LBaird119 at aol.com]

In a message dated 6/13/2011 10:01:45 A.M. Pacific Daylight Time,  
dieselwesty at yahoo.com writes:

Yes, I  would like to know as well.  Must you use a vacuum to suck 
everything out  
of the system?  How do you do this, is it a special AC guy only  tool?
 
  You pull a vacuum for 3 reasons.  To check if it holds (Ieaks),  to 
remove all (well, most all)
 un compressible gasses from the system, and to boil off water from  the 
system.  Of course 
a light flush would be required to chase all water and gasses out.
  The system will work with air and such in it, just not as  efficiently.  
Water will damage 
things and freeze up expansion valves
 
  I took an old refrigerator compressor, brazed the ends of the lines  shut 
and put on 
schraeder valves and tada!  A vacuum compressor that will also  transfer 
refrigerant 
or even work as an air compressor in a pinch!


I  have a good leak someplace and I want to remove the evaporater under the 
 dash 
to inspect for leaks as you had described in the past, look for dirt  
sticking to 
gooey stuff.
  You can pull the fan (it's a squeeze) and glove box and see the  
evaporator through 
the heater fan hole.  If it's all oily and dirty, it's leaking.   Replace 
it.


I  will replace the O-rings and re-install, but wondering about the 
evacuation of  
the system before trying to put more R12 in again.

Then, if it runs  for a day or 2 and leaks out again like it did the last 
time I 
tried  to fix it, I will have to put out the extra money for the colored 
gas and  
the special glasses to see the leak......as it is coming  out.




It's actually a liquid, fluorescent dye and is visible in normal  light 
even.  One 
refrig tech told me not to waste time on dyes and such if you know you have 
a leak.  Just look for the oily spots on any fittings, etc.  Find  and fix 
those 
and you likely won't have need for dye or sniffers.  
One  friend used to use the sniffer to detect leaks in vacuum operated 
door lock systems.  (R-12 was cheap then).  
     Loren